A little girl on a kibbutz is born pregnant and believes that her baby will be the Messiah. A Haitian-Jewish student comes to school on Purim in Muslim garb… with a bomb strapped to his chest. An image of the Virgin Mary appears in a synagogue before the High Holy Days.

In “Leaves of Grass,” Walt Whitman transformed his life into a poetic portrait of America and all its vastness, diversity, and tension. More than 150 years later, writer-director Tim Blake Nelson does something similar in his “Leaves of Grass,” a film that draws on his native Oklahoma, his college days at Brown, and his Jewish heritage.